Dan Gross, my colleague at Newsweek and Slate, pinged me the other morning after he had read the reports that Sarah Palin’s new book—suddenly announced for next month—would not be available as an e-book. Gross, a pioneer in e-book publishing long before Tina Brown, had noticed that Palin’s publisher was following Ted Kennedy’s by holding off on the e-book format. Ever alive to a budding trend, Gross figured two important instances presaged something more than a coincidence. Could I, Dan wanted to know, provide a third case, and was this preference on the part of publishers for withholding the e-book on the biggest titles an economic issue? (Gross’ column on this point can be found here.)

I replied that I did have a third example that proved the rule—Dan Brown’s The Lost Symbol—but the principle it revealed was less about the digital format and more about the role physical books play in the publishing industry.

Dan Brown’s publisher had been happy to supply the title in digital form. That allowed The Lost Symbol to sell more digital copies on the first day at Amazon than physical copies. This is because the thing of great value on the first day of sales was actually reading the book. (Merely owning it was not enough.) That’s something you can do whether you’ve read the book on paper or your Kindle.

With a big personality book, however, having read the book is far less important than owning it. These books are talismans, powerful objects that carry the aura of the person they’re associated with. That aura doesn’t attach to an e-book. You need something more substantial, at least something physical. When you buy a Kindle edition of a book, no one knows you’ve got it, no one can see you read it across an airplane aisle, and no one can admire it on your coffee table.

Another reason publishers are avoiding e-books for authors who sell their own fame is that the book itself is a bit of a luxury item. At $35, Kennedy’s publisher doesn’t want the e-book, with its $9.99 price, tarnishing the value of the physical book. Even if you don’t by the physical book for full price, you’re always going to feel ripped off by that $9.99 price being out there.

There’s nothing particularly new about talisman publishing. But a turning point came when Hillary Clinton released her book Living History in 2003. Here was a title bought for $8 million on the near-explicit premise that she would come clean about her husband. But in the time between the book deal and publication, Clinton had won a Senate seat and begun to position herself as a presidential contender. The idea that her book would be anodyne or unburdening was now laughable.

Yet it didn’t matter. The book sold shockingly well, earning back its unprecedented advance, setting up Bill’s own record-setting deal, and making the publisher plenty of profits. The source of the book’s success was no secret either. Women—and men—who bought the book were unabashed that they were showing her support in an unofficial straw poll. No one got together with their book group to discuss the book’s contents. Having read it was beside the point.

Hillary’s triumph was the industry’s triumph but also, in part, its undoing. Jack Welch was the first author to make good on a $7 million advance. Hillary pushed the bar to $8 million and Bill blew out the ceiling with his $12 million or more. Then came Alan Greenspan’s $8 million for a book that was published without a moment to spare; a few months after Greenspan’s book-tour-cum-victory lap, his reputation would collapse with the credit bubble he helped create. Can you see them publishing Greenspan’s book for that price today?

All those books made money. And if publishers had had the discipline or clairvoyance to have bought only those books, the business would be in better shape. But they didn’t. The $7 million-to-$8 million A-level books pulled up the B-level titles to unsustainable, brutal numbers. It’s hard to earn back $8 million dollars from book sales. It takes an indefatigable author with the stamina, will, and desire to go out and flog the book in person across the country, not just for the first few weeks but for months afterward.

Suddenly, that’s begun to change. That $8 million Kennedy book needs to sell roughly 500,000 copies to cover costs. The book sold 170,000 copies in the first week, a truly breathtaking number. And by the old math of opening weekends (you used to make 25 percent of your overall sales on a big-name book in the first week), Hachette was on its way to some cashflow. But even though the second week yielded a still-phenomenal 70,000 copies, the drop-off was steep and getting steeper. With months to go until Christmas, Hachette should be able to get to its magic number.

Sarah Palin’s $7 million advance will be a crucial test for both her and her publisher. Publisher and author have been smart to rush the book out while Palin still has a toehold in the public debate. Already their strategy is paying off. Palin made it to No. 1 on Amazon two days after the book was announced.

If she plays it like Hillary, the book could be a big comeback. Or, to mix political metaphors, this could be her Checkers speech, except unlike Nixon, she’ll get to play out that moment over and over again throughout the book tour/listening tour.

The Clintons taught us that in politics it’s vital to stay on message. That may be the final reason Palin’s publisher, consciously or not, is staying away from the e-book. Harper’s CEO, Brian Murray, told the Journal, "The publishing plan is focused on maximizing velocity of the hardcover before Christmas.”

Velocity comes from ubiquity, and ubiquity is what the modern publishing business is best at. Most people won’t buy Palin’s book in a bookstore; most of her buyers probably don’t have a bookstore they visit regularly. Instead, the bulk of sales will be in Wal-Marts, Krogers, Costcos, and newsstand chains like Hudson News. The first week or two—when most of those sales will take place—it won’t be hard for consumers to come across a copy of Going Rogue, so there’s no reason to divert from the big show even the small percentage of sales that e-books represent.

If the Palin book works—and it is beginning to look like she can make herself the key anti-Obama rallying point—it will be a reminder of the political power books can wield. Each sale will be a vote for Palin—though without the consequences of actually electing her; each book will also become a little campaign poster stoking her base and impressing her skeptics. Politics is media, and the publicity tour as trial campaign looks to be the last best hope of the publishing business.